Overlapping

[KirkH]

I know planes can't shoot at one another when their cards are overlapping, but can planes and stationary targets (balloons, AA guns, MG's) fire at each other if their cards overlap?

[Oberst Hajj]

This tends to be more of a house rule. If not using altitude, balloons should count as overlapping and not allow firing, ground targets should not and should be able to shoot as long as the target is in the firing arc.